In the pit, Idea Drilling is bringing up samples of old mining waste rock to give to MnDOT. That waste rock was the material used to make up a hull road at the bottom of the pit.

"Just the nature of this fill material is so abrasive and so hard, you might even think of this as sort of a driller's worst nightmare as far as trying to get through this material, but through a lot of effort we're being successful," said V.P. of Environmental Affairs for Idea Drilling, Marty Vadis.

It's a challenge for drilling and a challenge for MnDOT.

"[It's the] most challenging thing I've ever seen," said Highway 53 Project Director, Pat Huston, "It's [the material] really hard to classify, because it's under water and the samples don't come up normally like we're used to seeing them for ordinary highway projects... So engineers can't see it, they can't feel it, [they can only see] what comes up, and it's all kinds of different material."

Three of the options for the highway's new location would cross the Rouchleau Pit.

Engineers need to learn more about the material at the bottom of the pit to determine the best route to build.

"So, they'll bring up samples that we can take a look at and where they're really going to help us, they'll determine some of the material properties to help our engineers determine what we can build on there," said Huston.

MnDOT estimates that the relocation will cost $240 to $260 million, but they say there are a lot of unknowns right now and will have a better estimate as they learn more.